Roller for furnaces, particularly for iron and steel making furnaces for heating slabs or the like

Abstract: The invention relates to a roller for furnaces, particularly for iron and steel making furnaces for heating slabs, or the like, this roller being part of a sole consisting of a plurality of rollers substantially parallel to each other, and being provided with a plurality of annular collars (6, 6', 10) (annular riders) which are side by side and spaced apart, the rollers (1) and the annular collars (6, 6', 10) being cooled with a cooling fluid. According to the invention, the annular collars (annular riders) (6, 6', 10) are cooled by means of a flow of cooling fluid which is orientated transversely with respect to their axis and parallel to their median plane. The annular riders are made in tubular form and may be of toroidal form (6, 6') and are connected separately each to the supply duct (3) and to the return duct (2) for the cooling fluid. They may also be formed by the individual turns of a tubular spiral (10) or by a number of successive segments of a spiral which are connected via their ends to the supply duct (3) and to the return duct (2).

Description: The invention relates to a roller for furnaces, particularly for iron and steel making furnaces for heating slabs, or the like, this roller being part of a sole consisting of a plurality of rollers substantially parallel to each other and being provided with a plurality of toroidal chambers which are coaxial to the roller and distributed along it in spaced apart relationship, each toroidal chamber having a polygonal, square or circular cross section and being divided by a transverse partition while on opposite sides of thi.s partition an inlet and an outlet are provided, connected to an inner cooling system of the roller in such a manner, that the flow of the cooling fluid in each chamber is orientated transversely with respect to the axis of the roller and parallel to the median plane of the toroidal chambers. A roller of this kind is known from the document FR-A-512.892. In this known roller, each toroidal chamber is formed in a circular disk integral with two opposed central tubular hubs which are coaxial to the roller and communicate with the toroidal chamber on opposite sides of its transverse partition. The roller is composed of a plurality of these disks connected to each other by means of tubular roller portions screwed into the tubular hubs of the disks. It is an object of the invention to improve a roller of the type described initially, in such a way, as to render simpler and more economical its construction. The invention resolves the above problem with a roller according to the preamble of claim 1, characterized in that a) each toroidal chamber is formed by a tubular annular collar (6, 64) closed on itself around the roller (1) and fixed coaxially to the roller, b) the roller consists of two coaxial tubular cilindrical elements which are radially spaced apart forming two coaxial chambers, one of which is connected to the supply duct of the cooling system, while the other is connected to the return duct of the cooling system, c) the chamber of the tubular annular collar is connected on one side of its partition to the radially inner chamber of the roller by means of a connector tube, which passes through the radially outer chamber of the roller. Some further improvements of the roller according to the invention form the subject of the dependent claims. The particular characteristics of the invention and the advantages derived therefrom will be more clearly understood from the description of some preferred embodiments, illustrated by way of example and without restriction in the attached drawings, in which: Fig. 1 shows an axial section through a first embodiment of the roller with annular riders according to the invention; Fig. 2 shows an axial section through a second embodiment of the roller with annular riders according to the invention; Fig. 3 shows an enlarged axial section through the roller according to Fig. 1, at the location of an annular rider; Fig. 4 is an enlarged cross section through the roller according to Fig. 1, with the annular tubular rider partially in section; Fig. 5 is a view similar to Fig. 3 of a segment of the roller according to Fig. 2; Fig. 6 is a view similar to Fig. 4 of the roller according to Fig. 2; With reference to Figs. 1, 3 and 4, a roller 1 for a furnace, particularly for an iron and steel making furnace for heating slabs, consists of two coaxial tubular cylindrical elements 101, 201, which are spaced apart by spacers 4, forming two coaxial chambers 2, 3. At one end of the roller 1, the chamber 3 formed by the inner space of the inner tubular element 201 is connected to the supply duct of the cooling system, particularly that of the cooling water, while the outermost chamber 2, formed by the cylindrical space between the inner tubular element 201 and the outer element 101, is connected to the return duct of the cooling system. The connections are made, for example, by means of sealed rotary joints. At the opposite end of the roller 1, the two chambers 2 and 3 are closed and are connected together by means of through holes 5 made in the wall of the inner tubular element 201. This makes it possible to create a circulation of the cooling fluid in the end area of the roller 1 opposite the end where connection is made to the cooling system. At one end at least, preferably at the end where the chambers 2 and 3 are closed, the roller 1 has a termination 9 for rotary coupling to driving means, which are not illustrated. A number of annular tubular collars 6, forming what are known as riders, are provided outside the roller 1 and preferably distributed uniformly along it. The annular tubular riders 6 are closed on themselves to form tubular toroids. They have internal diameters greater than the external diameter of the roller 1, in other words that of the outer tubular element 101, and are fixed coaxially to the roller by means of spacers 7 which compensate for the effect of thermal expansion and contraction. The spacers and compensators 7 consist, for example, of U-shaped brackets placed between the outer peripheral surface of the roller 1 and the inner surface of the annular riders 6, to which they are connected with one of the opposite sides 107 in each case. The annular riders 6 have a rectangular or square cross section. Preferably the spacers and compensators 7 are fixed to the corresponding walls of the annular rider 6 and of the roller 1, with the free ends of the corresponding sides of the U profile. In particular, the spacers and compensators 7 have an extension in the axial direction with respect to the roller 1 corresponding to that of the annular collar 6. With reference to Figs. 3 and 4 in particular, each annular tubular rider 6 has a toroidal inner chamber 106 of square cross section. The chamber 106 is divided by a radial partition 206. At the location of the said partition 206 and on opposite sides of it, the toroidal chamber 106 communicates through an inlet connector 306 with the radially inner supply chamber 3 of the roller 1 and through an outlet connector 406 with the radially outer return chamber 2 of the roller 1. Each annular rider 6 is therefore connected in parallel to the supply and return ducts of the cooling system and has passing through it a flow of fluid orientated transversely with respect to its axis and parallel to its median plane. As may be clearly seen in Fig. 1, in the terminal areas and in the intermediate areas between the annular riders 6, the roller 1 is coated externally by a layer of refractory material 8 which is uniformly distributed over the peripheral surface of the roller 1 and which has a thickness such that the annular riders 6 project partially beyond it, at least with their radially external sides which support the iron or steel products. The annular riders are made of metallic material or of alloys capable of withstanding the heating temperatures inside the furnace. Figs. 2, 5 and 6 illustrate a second embodiment of the invention, the same reference numbers being used to indicate parts identical to those of the preceding embodiment according to Figs. 1, 3 and 4. This embodiment differs from the preceding one in respect of the shape of the annular tubular riders which are indicated by 6'. In this case, the annular tubular riders 6' and the toroidal chamber 106' have a substantially circular cross section; the said toroidal chamber is also divided by a radial partition 206' and is connected on opposite sides of the partition 206' to the supply chamber 3 and to the return chamber 2 respectively of the roller 1 by means of an inlet connector and an outlet connector 306', 406'. By contrast with the preceding embodiment, the annular tubular riders 6' are fixed with their radially inner sides joined to the outer peripheral surface of the outer tubular element 101 of the roller 1. The annular tubular riders 6' may advantageously be joined to the outer surface of the roller 1 with a flattened area 606' on their radially inner sides. They may be fixed by means of weld beads along the lateral edges of the said flattened area. The outer supporting surface of the annular tubular riders 6' consists of another flattened area 706' on their radially outer sides, opposite the roller 1. In the same way as in the preceding embodiment, the roller 1 is coated externally with one or more layers of refractory material, shown by a broken line and indicated by 8, this coating 8 having a thickness such that the annular riders 6' project partially beyond it, at least with their supporting flattened areas 706'. According to a characteristic substantially common to both embodiments, the section of the toroidal chamber 106, 106' for the cooling fluid is relatively large with respect to the overall section, having a radius equal to approximately half the overall external radius. Furthermore, the section of the supply chamber 3 of the roller 1 is relatively large with respect to the flow aperture of the return chamber 2 and to the overall section of the roller and has a radius which is approximately half the overall radius of the roller 1, or that of the outer element 101, while the return chamber 2 consists of a relatively thin space. In the embodiment shown in Figs. 1, 3 and 4, the section of the inlet and outlet connectors 306, 406 is substantially of the same order of magnitude as that of the chamber 106.

Claims: Roller for furnaces, particularly for iron and steel making furnaces for heating slabs, or the like, this roller (1) being part of a sole consisting of a plurality of rollers substantially parallel to each other and being provided with a plurality of toroidal chambers (106, 106') which are coaxial to the roller (1) and distributed along it in spaced apart relationship, each toroidal chamber having a polygonal, square or circular cross section and being divided by a transverse partition (206, 206'), while on opposite sides of this partition an inlet (306) and an outlet (406) are provided, connected to an inner cooling system of the roller in such a manner, that the flow of the cooling fluid in each chamber (106, 106') is orientated transversely with respect to the axis of the roller (1) and parallel to the median plane of the toroidal chambers (106, 106'), characterized in that a) each toroidal chamber (106, 106') is formed by a tubular annular collar (6, 64) closed on itself around the roller (1) and fixed coaxially to the roller (1), b) the roller (1) consists of two coaxial tubular cilindrical elements (101, 201) which are radially spaced apart forming two coaxial chambers (2, 3), one of which is connected to the supply duct of the cooling system, while the other (2) is connected to the return duct of the cooling system, c) the chamber (106, 106') of the tubular annular collar (6, 6') is connected on one side of its partition (206, 206') to the radially inner chamber (3) of the roller (1) by means of a connector tube (306, 306') which passes through the radially outer chamber (2) of the roller (1). Roller according to claim 1, characterized in that the tubular annular collar (6) has an internal diameter greater than the external diameter of the roller (1) and is fixed coaxially to the roller (1) in a radially spaced relationship by means of spacers (7) which compensate for thermal expansion and contraction, while the chamber (106) of the tubular annular collar (6) is connected on the other side of the partition (206) to the radially outer chamber (2) of the roller (1) by means of a connector tube (406) which passes through the radially space between the tubular annualr collar (6) and the roller (1). Roller according to claim 2, characterized in that the spacers (7) have a U-shaped transverse section with respect to the axis of the roller (1) and are fixed by the opposite sides of their U-shape, preferably only in the area of their free ends, to the facing surfaces of the roller (1) and the annular tubular collar (6). Holler according to claim 1, characterized in that the tubular annular collar (6') is fixed with its radially inner wall directly to the outer wall of the roller (1) and its chamber (106) is connected on the other side of the partition (206') to the radially outer chamber (2) of the roller (1) by means of coinciding holes (406') provided in the radially inner wall of the tubular annular collar (6') and in the radially outer wall of the roller (1). Roller according to claim 4, characterized in that the tubular annular collar (6') has a flattened area (606) on its inner side facing the outer peripheral surface of the roller (1) and is welded to the wall of the roller (1). Roller according to one or more of the preceding claims, characterized in that the radially external surface of the tubular annullar collar (6, 6') consists of a flattened area (706, 706') parallel to and coaxial with the outer surface of the roller. Roller according to one or more of the preceding claims, characterized in that the two coaxial chambers (2, 3) of the roller (1) are connected to the supply duct and to the return duct fo the cooling system at one end of the roller (1), while at the opposite end they are closed and communicate (5) with each other. Roller according to one or more of the preceding claims, characterized in that the roller (1) is coated externally with a layer of refractory material (8) having a thickness such that the tubular annular collars (6, 6') project, at least with their radially external supporting sides (706), partially beyond the outer peripheral surface of the layer of refractory material (8).

Inventors: DEPLANO STEFANO, MILLONE ROBERTO, PATRONE MAURIZIO, DEPLANO, STEFANO, MILLONE, ROBERTO, PATRONE, MAURIZIO
Applicants: TECHINT SPA, TECHINT - COMPAGNIA TECNICA INTERNAZIONALE S.P.A.
Application year: 1994
Main classification: F27D3
IPC codes: F27D9, F27D3